In recent years the popularity of sailboarding or wind surfing has increased dramatically. The sport began approximately 17 years ago by mounting a mast and sail assembly on a surfboard and has progressed to nationally televised highly skilled contests. In addition to the water-based sport sailboard sail assemblies even have been added to skateboards.
Initially, sailboards were constructed with masts which were pivotally mounted to the body of the board by a universal joint, which would not support or sustain the mast by itself above the board. These sailboards are in widespread use today, but control of the motion of a sailboard having a mast with a universal joint is very difficult to learn and master. Steering of such sailboards is based upon manipulation of a combination of the mast, the boom and the sailor's body position on the board.
The basic patent in the sailboarding field is U.S. Pat. No. 3,487,800 to Schweitzer et al. This patent sets forth the mast-boom-sail assembly which enables steering of the sailboard without using a steerable rudder. The mast of the sailboard is coupled to the board body by a universal joint so that the mast can be inclined or tilted from the vertical by a standing rider while the mast-boom-sail assembly is pivoted around the universal point. The combined mast tilting, boom swinging and movement of the rider's body weight on the board can be used to turn the board. When employed by a highly skilled user, the unsupported, universal joint mounted mast is very effective as a means for controlling board motion, and it provides one solution to the problem of how to steer the board while standing.
More recently sailboards have been devised in which a steerable rudder has been provided for use in combination with a tiltable, universal joint mounted mast. Typical of such sailboards is the sailboard set forth in German Patent No. 2,731,266 to Schwaiger. The Schwaiger patent discloses a sailboard having a foot operated steering system which allows the sailor to control the board's direction of travel without the need for large fore-and-aft displacements of the mast-boom-sail assembly, as is required for universal joint mounted masts which do not have steerable rudders. Sailboards with universal joint masts without steerable rudders usually are able to negotiate only slow or wide turns, making collision avoidance difficult. It is also quite common to submerge the bow of such universal joint mounted sailboards without steerable rudders while tilting the sail forward to change direction. Thus, the Schwaiger steerable rudder enhances turning and provides a simple, efficient method of steering a sailboard with a universal-jointed mast.
Still more recently, sailboards have been created in which the mast is fixed and self-supporting on the sailboard. Thus, German Patent No. 3,123,967 to Horn discloses a sailboard in which there is a fixed, non-tiltable mast that is used in conjunction with a foot-operated steering system. This form of sailboard eliminates the considerable effort even a highly skilled user must expend to coordinate the tricky task of erecting the mast-boom-sail assembly and maintaining the assembly in a substantially vertical position while the wind force tends to knock the assembly down. Thus, a fixed mast sailboard allows novices and a broader spectrum of individuals to take up the sport without the frustration of having the mast assembly continually fall into the water and without the back-straining effort of again erecting the assembly. Instead of the sailor trying to balance himself and the mast-boom-sail assembly, which may be buffeted by unsteady wind forces, he can now use the fixed mast to actually steady himself and the relatively narrow and unstable sailboard.
The fixed mast sailboard, however, also is not without its disadvantages. When beating to windward (close-hauled) the sailboard boom occupies a substantial portion of the sailboard centerline. Thus, in a light wind when the sailor is not leaning out, the boom tends to push the sailor backwards off the board when he tries to sail close-hauled. This is particularly true for wide boom assemblies such as are used in modern, highly cambered sails with the sailor standing forward near the mast. Since the mast cannot be tilted away from the sailor in a fixed boom sailboard, specialized booms, such as are disclosed in the German patent to Horn, must be employed.
Additionally, when sailing a fixed mast sailboard in heavy winds, the sailor must lean away from the boom to a substantial degree in order to produce sufficient righting moment to counter the heeling moment produced by the large wind force on the sail. Since the sailor cannot tilt the mast, some provision must be made for extending the sailor's reach to the boom, such as by boom extension assemblies or handles for high-wind sailing.
Additionally, steerable rudders on sailboards have typically included complex assemblies which have inhibited steering of the rudder in order to enable frictional securement of the rudder in any angular orientation. Moreover, sailboards having steerable rudders usually position the rudder steering mechanism in a single location, whereas the sailor is often required to move fore and aft on the board to maximize maneuvering.
While kick-up types of rudders are known in the sailing art, for example, U.S. Pat. Nos. 4,218,986 and 4,319,538, such mechanisms are not readily adaptable for use on sailboards having foot operated steering mechanisms.